'98 Explorer "chirping"

It's probably your belt tensioner but could be the belt or the idler pulley. H

Thanks for the help "H", I did replace the tensioner pulley and idler pulley and the belt was replaced approx. 1 year ago. Think it's the water pump going out???

It's possible, but I'd try to eliminate everything else, first. Did you replace the tensioner pulley, or the whole tensioner assy? Not all belts are created equal. Even though it's only a year old, it could be causing the chirp. I have sprayed a little WD-40 on belts to see if that would stop the chirp. A mechanic's stethoscope or long thin screwdriver should help find the chirp, if it's the waterpump. H

Yes, i have replaced the tensioner assembly. Thanks for the advice, i'll try those options.

Back in Feburary 2004 I had the same problem with my 97 Mountaineer. I described it as a chirping and it would come and go and was a "bear" to figure out. I changed all the things that other have posted and was getting ready to change the water pump out of frustration. I will bet good money that the noise is coming where the old fashion ignition distributor was. It has been replaced by a Cam Sensor Positioner which is a long metal shaft that goes into the engine hole where the distributor use to sit. On a v8 it is in the front of the engine, and A v6 it's in the rear. On top of the cam sensor postioner is a plastic piece which is mounted on top of the cam postioner shaft. This plastic piece is infamous for having a little magnet inside the housing that breaks loose and grinds against the revolving metal shaft.This makes the weirdest noise including chirping and a loud "howling" sound sometimes. If you need more information on how to replace this piece or questions, please let me know. It's only about $35.00 bucks but will cost you hundreds of dollars if a dealer does it. Good luck!